Generally components in an electronic assembly are used to perform some operation on or processing of an electrical signal. This processing may include simply transporting electrical signals from their respective sources to their intended destinations. Depending on the characteristics of the signals to be transported this may be a comparatively straightforward undertaking, in for example the case where the signal is a zero or low frequency signal or it may be significantly more difficult, where for example the signal is a high frequency or radio frequency signal.
In the latter case, the electromagnetic propagation properties of the high frequency signals results in significant obstacles to the efficient and uncorrupted transport of the electrical energy represented by such signals. Such a high frequency signal is not readily constrained to an intended path. If the high frequency signal has a very low power or energy level it can be subject to interference from other signals or alternatively if the high frequency signal has a relatively high power or energy level it may interfere with other signals. Practitioners have developed various structures to deal with the aforementioned problems.
These structures are variously known as transmission lines or coaxial transmission lines or strip lines depending on the specific characteristics or configuration of the structure and most serve to one extent or another to facilitate the efficient and uncorrupted transport of the electrical energy represented by such high frequency signals. The coaxial transmission line is a particularly advantageous configuration for efficiently transporting high frequency energy and providing excellent isolation between the desired signal and other signals, thus avoiding the problems of corruption. The coaxial transmission line configuration when used in electronic assemblies often takes the form of a semi-rigid coaxial cable with a round cross section.
While working well for uncorrupted signal transport, the round semi-rigid coaxial configuration presents a number of difficulties that must be dealt with by the manufacturing process that produces electronic assemblies. Dealing with these difficulties places an economic burden on the manufacturing process that uses such semi-rigid coaxial cables. To begin with the semi-rigid coaxial cables are relatively expensive. In addition they are made from a different material than the typical printed circuit board substrate often used to carry the components in a given electronic assembly. This mismatch in materials may contribute to different thermal characteristics such as expansion or contraction over temperature and hence additional precautions to avoid damage that may result from the mismatch or alternatively a lower quality electronic assembly. Furthermore the round cross section of the semi-rigid coaxial cable is difficult to work with in automated assembly processes. This cross section does not lend itself to automated pick and place operations.
Clearly a need exists for a reliable and inexpensive transmission line component that is readily adaptable to state of the art electronic assembly manufacturing processes.